Optimal Day Ahead Planning and Bidding Strategy for Participating in Frequency Markets with a Specific Battery : Study of the Technical and Economic Viability

Abstract: The growing need of grid stability derived from the current energy transition is favouring the expansion of the ancillary services markets. Thanks to their fast response, this situation can be exploited by different kinds of batteries, even by those that were initially designed for a different application. However, each regulation product presents different market rules that are also country dependent. For this reason, it is important to ensure that the batteries in question count on the right characteristics. This project is focused on an energy storage system conceived for a number of applications not including ancillary services. With the aim of determining if that battery could find a new revenue stream in balancing markets, a study of the most relevant frequency markets has been conducted. After identifying those in which the battery could take part according to its technical features, a mathematical model has been developed. The model provides the optimal bidding strategy for the day ahead auctions of the selected markets and the most convenient operational planning for the day of delivery. Thanks to the model, the battery has been proved to be able to make profits from participating in the Swedish Frequency Containment Reserve (FCR) markets while it is not being occupied in its main intended applications. Furthermore, it will be possible to increase those profits by competing in the Swedish Fast Frequency Reserve (FFR) market, once the daily auctions are implemented.